The stator of a dynamoelectric machine such as an electric motor or generator typically includes a core of magnetic material having an axially extending bore for receiving a rotor. The core typically is formed from a plurality of identical laminations which are aligned and arranged in a stack held together by clips. Each lamination includes a plurality of teeth which extend radially into the bore. Slots between each of the teeth extend radially outwardly from the bore. The ends of the teeth and the open ends of the slots define the periphery of the bore.
A plurality of coils formed from insulated conductive wire are inserted into selected core slots with portions of the coils at the ends of the core forming end turn regions. The coils are interconnected to form coil groups or poles. The conductive wires which form the coils, are sometimes referred to as stator windings. As an example, a single speed motor typically includes coil groups which establish at least one main winding and an auxiliary or start winding.
To insert the coils into the stator core slots, it is known to form coil groups with coil forms in a winding machine, locate the coil groups on coil insertion (or injection) tooling, and then move the coil groups from the coil insertion tooling to a stator with portions thereof located in stator slots. Winding machines including coil forms are described, for example, in U.S. Pat. No. 3,977,444, which is assigned to the present assignee.
Known winding machines typically include two coil forms separated by a preselected distance, and a flyer arm which rotates around the forms. The windings are formed as the flyer arm wraps the insulated wire on segments of the forms. In order to ensure that the resulting windings have the desired dimensions for a particular stator configuration, the coil forms must be separated at a precise separation distance. This distance is sometimes referred to as winding or coil form spread.
Currently, an operator uses various blocks cut to specific dimensions to set the coil form spread. Specifically, and depending upon the particular windings to be formed, the operator selects the corresponding block. The operator locates the block between the forms and then sets the forms so that the forms correspond to the particular block size. In the event that an incorrect coil form spread is selected by the operator, it may be necessary to discard any stators fabricated using the windings wound on the incorrectly set forms.
It would be desirable to provide apparatus and methods for setting the coil form spread which do not rely upon the experience and knowledge of an operator and which provide accurate and consistently correct coil form spreads. It also would be desirable to provide such apparatus and methods which are inexpensive to implement and can be utilized in connection with existing winding machines.